Question

about a hundred years ago, when small pox persisted, a group of people who had this disease earlier, survived as they had no chance of suffering from it again. So, having the disease once was mean of preventing the subsequest attack of the same disease 1) why does this happen? explain 2) can we 'fool' the immune system? explain. 3) name this principle of prevention of disease.

Answer 1

Answer:

The high case fatality rate of approximately 30 percent (for the variola major virus strand) meant that smallpox shortened the lives of many. Since the virus predominantly affected children during endemic periods, smallpox deaths are likely to have had a disproportionate impact on average life expectancy.Smallpox is caused by infection with the variola virus. The virus can be transmitted: Directly from person to person.